In backlight units of liquid crystal displays, light diffusing sheets are used in order to erase light diffusion patterns of light guide plates and increase brightness for the frontal direction. As such light diffusing sheets, light diffusing sheets comprising a support and a light diffusing layer containing a transparent binder resin and plastic beads and provided on one side of the support are generally used.
Higher brightness for the frontal direction is desired especially for liquid crystal displays in recent years, and therefore light diffusing sheets are also desired to have a performance of increasing brightness for the frontal direction.
In order to increase brightness for the frontal direction, it is possible to design surface profiles of light diffusing sheets to be optimal profiles. However, more conveniently, methods of increasing thickness of the light diffusing layer, increasing particle size of plastic beads in the light diffusing layer, increasing content of the plastic beads and so forth are used (Patent document 1).    Patent document 1: Japanese Patent Unexamined Publication (KOKAI) No. 8-75909 (claims)